Ignore:
Timestamp:
2019-12-04T11:51:54+01:00 (12 months ago)
Author:
laurent
Message:

Writing the doc for SBCBLK!

Location:
NEMO/branches/2019/dev_r11085_ASINTER-05_Brodeau_Advanced_Bulk/doc/latex/NEMO
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2 edited

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  • NEMO/branches/2019/dev_r11085_ASINTER-05_Brodeau_Advanced_Bulk/doc/latex/NEMO/main/bibliography.bib

    r11831 r12046  
    400400} 
    401401 
    402 @article{         brodeau.barnier.ea_JPO16, 
    403   title         = "Climatologically Significant Effects of Some Approximations in the Bulk Parameterizations of Turbulent AirSea Fluxes", 
     402@article{         brodeau.barnier.ea_JPO17, 
     403  title         = "Climatologically Significant Effects of Some Approximations in the Bulk Parameterizations of Turbulent Air{\textendash}Sea Fluxes", 
    404404  pages         = "5--28", 
    405405  journal       = "Journal of Physical Oceanography", 
     
    407407  number        = "1", 
    408408  author        = "Brodeau, Laurent and Barnier, Bernard and Gulev, Sergey K. and Woods, Cian", 
    409   year          = "2016", 
     409  year          = "2017", 
    410410  month         = "jan", 
    411411  publisher     = "American Meteorological Society", 
     
    31343134  doi           = "10.1029/92jc00911" 
    31353135} 
     3136 
     3137@article{large.yeager_CD09, 
     3138author="Large, W. G. and Yeager, S. G.", 
     3139title="The Global Climatology of an Interannually Varying Air-Sea Flux Data Set", 
     3140pages = "341--364", 
     3141journal="Climate Dynamics", 
     3142volume = "33", 
     3143number = "2-3", 
     3144year="2009", 
     3145month = "aug", 
     3146publisher = "Springer Science and Business Media LLC", 
     3147doi="10.1007/s00382-008-0441-3" 
     3148} 
     3149 
  • NEMO/branches/2019/dev_r11085_ASINTER-05_Brodeau_Advanced_Bulk/doc/latex/NEMO/subfiles/chap_SBC.tex

    r12031 r12046  
    4747 
    4848\begin{itemize} 
    49 \item a bulk formulation (\np[=.true.]{ln_blk}{ln\_blk} with four possible bulk algorithms), 
     49\item a bulk formulation (\np[=.true.]{ln_blk}{ln\_blk}), featuring a selection of four bulk parameterization algorithms, 
    5050\item a flux formulation (\np[=.true.]{ln_flx}{ln\_flx}), 
    5151\item a coupled or mixed forced/coupled formulation (exchanges with a atmospheric model via the OASIS coupler), 
     
    537537\label{sec:SBC_blk} 
    538538 
     539% L. Brodeau, December 2019... 
     540 
    539541\begin{listing} 
    540542  \nlst{namsbc_blk} 
     
    543545\end{listing} 
    544546 
    545 In the bulk formulation, the surface boundary condition fields are computed with 
    546 bulk formulae using prescribed atmospheric fields and prognostic ocean (and 
    547 sea-ice) surface variables averaged over \np{nn_fsbc}{nn\_fsbc} time-step. 
     547If the bulk formulation is selected (\np[=.true.]{ln_blk}{ln\_blk}), the air-sea 
     548fluxes associated with surface boundary conditions are estimated by means of the 
     549traditional \emph{bulk formulae}. As input, bulk formulae rely on a prescribed 
     550near-surface atmosphere state (typically extracted from a weather reanalysis) 
     551and the prognostic sea (-ice) surface state averaged over \np{nn_fsbc}{nn\_fsbc} 
     552time-step(s). 
    548553 
    549554% Turbulent air-sea fluxes are computed using the sea surface properties and 
     
    555560\subsection{Bulk formulae} 
    556561% 
    557 In NEMO, when the bulk formulation is selected, surface fluxes are computed by means of the traditional bulk formulae: 
     562In NEMO, the set of equations that relate each component of the surface fluxes 
     563to the near-surface atmosphere and sea surface states writes 
    558564% 
    559565\begin{subequations}\label{eq_bulk} 
     
    568574  \end{eqnarray} 
    569575\end{subequations} 
    570 %lulu 
    571 % 
    572 From which, the the non-solar heat flux is \[ Q_{ns} = Q_L + Q_H + Q_{ir} \] 
    573 % 
     576% 
     577with 
    574578   \[ \theta_z \simeq T_z+\gamma z \] 
    575579   \[  q_s \simeq 0.98\,q_{sat}(T_s,p_a ) \] 
    576  
    577  
    578  
     580% 
     581from which, the the non-solar heat flux is \[ Q_{ns} = Q_L + Q_H + Q_{ir} \] 
     582% 
    579583where $\mathbf{\tau}$ is the wind stress vector, $Q_H$ the sensible heat flux, 
    580584$E$ the evaporation, $Q_L$ the latent heat flux, and $Q_{ir}$ the net longwave 
     
    584588and longwave radiative fluxes, respectively. 
    585589% 
    586 Note: a positive sign of $\mathbf{\tau}$, $Q_H$, and $Q_L$ means a gain of the 
    587 relevant quantity for the ocean, while a positive $E$ implies a freshwater loss 
    588 for the ocean. 
    589 % 
    590 $\rho$ is the density of air. $C_D$, $C_H$ and $C_E$ are the BTCs for momentum, 
    591 sensible heat, and moisture, respectively.  $C_P$ is the heat capacity of moist 
    592 air, and $L_v$ is the latent heat of vaporization of water.  $\theta_z$, $T_z$ 
    593 and $q_z$ are the potential temperature, temperature, and specific humidity of 
    594 air at height $z$, respectively. $\gamma z$ is a temperature correction term 
    595 which accounts for the adiabatic lapse rate and approximates the potential 
    596 temperature at height $z$ \citep{Josey_al_2013}.  $\mathbf{U}_z$ is the wind 
    597 speed vector at height $z$ (possibly referenced to the surface current 
    598 $\mathbf{u_0}$, section \ref{s_res1}.\ref{ss_current}). The bulk scalar wind 
    599 speed, $U_B$, is the scalar wind speed, $|\mathbf{U}_z|$, with the potential 
    600 inclusion of a gustiness contribution (section 
    601 \ref{s_res2}.\ref{ss_calm}). 
    602 $P_0$ is the mean sea-level pressure (SLP). 
     590Note: a positive sign of $\mathbf{\tau}$, the various fluxes of heat implies a 
     591gain of the relevant quantity for the ocean, while a positive $E$ implies a 
     592freshwater loss for the ocean. 
     593% 
     594$\rho$ is the density of air. $C_D$, $C_H$ and $C_E$ are the bulk transfer 
     595coefficients for momentum, sensible heat, and moisture, respectively (hereafter 
     596referd to as BTCs). 
     597% 
     598$C_P$ is the heat capacity of moist air, and $L_v$ is the latent heat of 
     599vaporization of water. 
     600% 
     601$\theta_z$, $T_z$ and $q_z$ are the potential temperature, absolute temperature, 
     602and specific humidity of air at height $z$ above the sea surface, 
     603respectively. $\gamma z$ is a temperature correction term which accounts for the 
     604adiabatic lapse rate and approximates the potential temperature at height 
     605$z$ \citep{Josey_al_2013}. 
     606% 
     607$\mathbf{U}_z$ is the wind speed vector at height $z$ above the sea surface 
     608(possibly referenced to the surface current $\mathbf{u_0}$, 
     609section \ref{s_res1}.\ref{ss_current}). 
     610% 
     611The bulk scalar wind speed, namely $U_B$, is the scalar wind speed, 
     612$|\mathbf{U}_z|$, with the potential inclusion of a gustiness contribution 
     613(section \ref{s_res2}.\ref{ss_calm}). 
     614% 
     615$a$ and $\delta$ are the albedo and emissivity of the sea surface, respectively.\\ 
     616% 
     617%$p_a$ is the mean sea-level pressure (SLP). 
     618% 
    603619$T_s$ is the sea surface temperature. $q_s$ is the saturation specific humidity 
    604620of air at temperature $T_s$ and includes a 2\% reduction to account for the 
    605621presence of salt in seawater \citep{Sverdrup_al_1942,Kraus_Businger_1996}. 
    606 Depending on the bulk parameterization used, $T_s$ can be the temperature at the 
    607 air-sea interface (skin temperature, hereafter SSST) or at a few tens of 
    608 centimeters below the surface (bulk sea surface temperature, hereafter SST). 
     622Depending on the bulk parameterization used, $T_s$ can either be the temperature 
     623at the air-sea interface (skin temperature, hereafter SSST) or at typically a 
     624few tens of centimeters below the surface (bulk sea surface temperature, 
     625hereafter SST). 
     626% 
    609627The SSST differs from the SST due to the contributions of two effects of 
    610 opposite sign, the \emph{cool skin} and \emph{warm layer} (hereafter CSWL). The 
    611 \emph{cool skin} refers to the cooling of the millimeter-scale uppermost layer 
    612 of the ocean, in which the net upward flux of heat to the atmosphere is 
    613 ineffectively sustained by molecular diffusion. As such, a steep vertical 
    614 gradient of temperature must exist to ensure the heat flux continuity with 
    615 underlying layers in which the same flux is sustained by turbulence. 
    616 The \emph{warm layer} refers to the warming of the upper few meters of the ocean 
    617 under sunny conditions. 
    618 The CSWL effects are most significant under weak wind conditions due to the 
    619 absence of substancial surface vertical mixing (caused by \eg breaking waves). 
    620 The impact of the CSWL on the computed TASFs is discussed in section 
    621 \ref{s_res1}.\ref{ss_skin}. 
    622  
    623  
    624 %%%% Second set of equations (rad): 
    625 where $a$ and $\delta$ are the albedo and emissivity of the sea surface, 
    626 respectively. 
    627 Thus, we use the computed $Q_L$ and $Q_H$ and the 3-hourly surface downwelling 
    628 shortwave and longwave radiative fluxes ($Q_{sw\downarrow}$ and 
    629 $Q_{lw\downarrow}$, respectively) from ERA-Interim to correct the daily SST 
    630 every 3 hours. Due to the implicitness of the problem implied by the dependence 
    631 of $Q_{nsol}$ on $T_s$, this correction is done iteratively during the 
    632 computation of the TASFs. 
     628opposite sign, the \emph{cool skin} and \emph{warm layer} (hereafter CS and WL, 
     629respectively). 
     630% 
     631Technically, when the ECMWF or COARE* bulk parameterizations are selected 
     632(\np[=.true.]{ln_ECMWF}{ln\_ECMWF} or \np[=.true.]{ln_COARE*}{ln\_COARE\*}), 
     633$T_s$ is the SSST, as opposed to the NCAR bulk parameterization 
     634(\np[=.true.]{ln_NCAR}{ln\_NCAR}) for which $T_s$ is the bulk SST (\ie~temperature 
     635at first T-point level). 
     636 
     637 
     638For more details on all these aspects the reader is invited to refer 
     639to \citet{brodeau.barnier.ea_JPO17}. 
    633640 
    634641 
     
    654661\subsubsection{Appropriate use of the  NCAR algorithm} 
    655662 
    656 NCAR bulk parameterizations (formerly know as CORE) is meant to be used with the CORE II atmospheric forcing (XXX). Hence the following namelist parameters must be set as follow: 
     663NCAR bulk parameterizations (formerly know as CORE) is meant to be used with the 
     664CORE II atmospheric forcing \citep{large.yeager_CD09}. Hence the following 
     665namelist parameters must be set: 
    657666% 
    658667\begin{verbatim} 
     
    758767 
    759768thanks to the \href{https://brodeau.github.io/aerobulk/}{Aerobulk} package 
    760 (\citet{brodeau.barnier.ea_JPO16}): 
     769(\citet{brodeau.barnier.ea_JPO17}): 
    761770 
    762771The choice is made by setting to true one of the following namelist 
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